ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ → it is impossible to step twice in the same river, you cannot step twice into the same rivers
P. and V. πείθειν, ἀναπείθειν (Eur., Helen 825), V. ἔκπείθειν.
be convinced, be sure: see under sure.
